Beneath the high ceilings of a factory in the wheat fields of Emilia-Romagna in northern Italy, Lamborghini engineers are building a new supercar. Called the Aventador, it has been described as the closest thing to a stealth fighter jet you'll see on the road. It's also a high-profile symbol of a strategic battle taking shape in the auto industry.

Silhouetted against grey walls, workers in black polo shirts adorned with Lamborghini's gold raging bull logo guide sheets of black material into a vacuum-controlled cutting machine, before pressing and shaping the pieces into huge molds. These parts will make the chassis of the Aventador, which is one of the first cars to have its entire body built of carbon fiber composites, an alternative to metals prized by plane-makers for their lightweight malleability and strength. The materials give designers "freedom to design aggressively," says Lamborghini's Technology Manager Massimiliano Corticelli.

The materials — plastics reinforced by synthetic fibers — will also allow the kind of performance so important to Lamborghini drivers: 0-60 mph in 2.9 seconds with a top speed of around 217 mph. But their potential value lies beyond the handful of people who can pay a starting price of $355,000 for a car that rolls off the assembly line at just 20 a week.

Partly as a consequence of emissions reduction targets, mass-market automakers need to produce lighter cars. For the next few years, automakers such as Fiat and Volkswagen expect weight reductions to come largely from using aluminum. But composites are 30 percent lighter than aluminum and 50 percent lighter than steel. If carmakers can get the price down — composites currently cost at least 10 times as much as aluminum and 30 times as much as steel, according to Volkswagen — they hope to be able to use them in the mass market.

"We have been working on making cars lighter for several years, but the tightening up of regulation for reducing emissions by 2020 makes it necessary in reality to move towards breakthrough solutions," says Louis David, materials expert at French car maker PSA Peugeot Citroen.

There is progress. Peugeot and other carmakers already make some small parts out of composite material but do not yet use the technology for large parts. But BMW, which plans by the end of 2013 to roll out electric cars with entire passenger cabins made from a composite known as carbon fiber reinforced plastic (CFRP), is leading the race.

The BMW i3, which made its North American debut at the LA auto show in November, is an urban electric car wrapped in carbon fiber. Set to debut in 2013 as a 2014 model, the i3 will be able to travel up to 100 miles on a charge and reach top speeds of 93 mph, while a gasoline-powered generator will extend range.

"So far, there is no carmaker that is banking on carbon fibers quite like BMW," says Reto Hess, who coordinates global car industry analysis for Credit Suisse's private banking arm.

Too pricey

Taking composites mass market won't be easy.

Fiat has long been using composite technology — its Alfa Romeo 8C contains about 200 pounds of the stuff — but like other car makers, it is still exploring what the technology can do on a larger scale.

Cars built from carbon fiber parts will have to meet the same safety criteria as conventional ones; composites can potentially cut a car's mass by half, says PSA's David. But on costs, he is blunt: "Today we believe that composites that are competitive for the automotive industry in terms of cost and production rhythm do not exist," he says. The company is taking "baby steps" in using the materials in vehicles that should be in showrooms by 2014-15, and he expects the technology to be much more widespread by 2018.

Secure supply

BMW isn't waiting. It won't disclose its investment, but according to German media reports it has spent more than $1.3 billion on developing the technology and its new range of "i" electric vehicles and plug-in hybrids. Whole cars made of carbon fiber composites will be available from 2013.

Its strategy is based on the view that trendsetting car buffs with deep pockets will develop a taste for electric cars, especially if prodded by government incentives. The company says the i3's bodywork will be 550-770 pounds lighter than that of a conventional car of the same size. With a much lighter chassis, it hopes its traditional clientele of drivers could even desire a premium electric vehicle for city driving.

BMW finance chief Friedrich Eichiner says the company is already working to cut costs to a point where they will be level with aluminium. It's a goal that can only be achieved with economies of scale. "Costs are a function of the volumes — that remains the driver," Eichiner says.

To this end, BMW has already secured fiber production capacity which industry experts say is equivalent to what the entire car industry consumed last year. Since 2011, the company has sourced its carbon fiber reinforced plastics through a joint venture with Europe's only major producer of carbon fibers, German-based SGL Carbon.